British Patent 1,489,175 corresponds to U.S. patent application Ser. No. 607,175, filed Aug. 25, 1975, and discloses a microscope ocular of simple configuration which is also suitable for wearers of spectacles. The ocular comprises two groups of which one group consists of a single lens and the other group consists of a two-element composite lens. For manufacture, it is advantageous that an outer surface of the composite lens is a planar surface. The curved surfaces of this ocular are all spherical; however, a disadvantage of this ocular is the relatively small apparent viewing angle of approximately 44.degree.. Small viewing angles of this kind do not satisfy the requirements imposed today on a wide-angle ocular.
U.S. Pat. No. 5,162,945 discloses oculars of simple configuration for binoculars and telescopes wherein the apparent viewing angle is 56.degree.. The simplest embodiments which exhibit a rather good correction likewise have a two-component configuration. One component is a single lens having an aspherical surface and the second component is a two-component composite lens. All lens surfaces are curved as shown by the corresponding construction parameters. In this way, a greater complexity for the manufacture of the composite lens results than for the ocular according to British Patent 1,489,175.